The invention relates to a method of doping a semiconductor body by diffusion from the gaseous phase in which centres of impurity are diffused into a limited area of one surface of a semiconductor body.
Such a method finds application, as known, in planar technology. Usually, silicon dioxide is used as a diffusion mask which can arrest the oxides of doping materials for a certain time so that they do not come into contact with the semiconductor body. However, it is desirable, in many cases, either to be able to diffuse for longer periods or to be able use thinner diffusion masks.